The present invention relates to an inflatable cushion and more particularly to a safety device for use in a motor vehicle. The present invention is particularly useful in application as an inflatable side curtain for disposition between a vehicle occupant and the vehicle frame during a roll-over event.
Inflatable protection cushions used in passenger vehicles are a component of a relatively complex system. The main elements of such a system are: an impact sensing system, an ignition system, a gas producing device, an attachment device, a system enclosure and an inflatable protective cushion. Upon sensing an impact, the gas is released causing an explosive release of gas filling the cushion to a deployed state which can absorb the impact of the forward movement of a body. Such cushions were initially used to protect the operator of a vehicle and were stored within the steering column for this purpose. Such driver side cushions are described in U.S. Pat. No. 5,533,755 to Nelsen et al. (incorporated by reference). Cushions for the protection of vehicle passengers have gained acceptance and are typically stored in the dash panel in opposing relation to the passenger seat. Recently, the use of cushions for the protection of drivers and occupants in side-impact collisions has gained general acceptance.
One cushion configuration for use in the protection of vehicle occupants during a side-impact collision is the so called side curtain configuration which is stored at the roof line and connected along the door frame. One embodiment of such a side curtain is illustrated and described in U.S. Pat. No. 5,788,270 to HAland et al., the teachings of which are incorporated herein by reference.
As explained in HAland et al. one of the purposes of the side curtain configuration is to remain inflated for a relatively long period of time so as to provide protection to the vehicle occupants in the event of a protracted roll-over event. Thus, unlike traditional driver and passenger side cushions which must rapidly deflate upon impact by the occupant to be protected, the side curtain must remain inflated in order to be effective. Accordingly, uncontrolled or excessive release of the inflation media through seams or other connective links within the side curtain is undesirable.
Aside from the need to control the inflation of the side curtain, it is also necessary that the curtain be of such a configuration as to provide substantial protection over an extremely large area during its operation. By way of example only, it may be necessary to span the entire length of the passenger compartment so as to protect both the driver and any rear seated passenger simultaneously in a collision. As will be appreciated, in order for the side curtain to perform, its configuration must be such as to provide an effective expanded profile while at the same time providing for the rapid efficient channeling of the inflation media to all areas of the cushion which are to be inflated. In order to achieve these goals, side cushions such as those described in HAland et al. have been configured so as to have a relatively thin profile of about 30-40 millimeters upon inflation. Such a thin profile is achieved by interweaving the fabrics forming the front and the back of the curtain at selected locations during formation of the curtain on a jacquard controlled loom.
The interweaving technique as utilized by HAland is described in detail in International Patent Publication WO/90/09295 which corresponds to U.S. Pat. No. 5,685,347 to Graham et al. the teachings of which are incorporated herein by reference. As taught in Graham, interweaving and consequential control of the shape of the airbag may be effected through use of a loom having programming means such as a jacquard system. However, the use of such jacquard systems introduces a high level of complexity into the formation process. As will be appreciated by those of skill in the art, a jacquard system uses a complex computer controlled process or a series of punched cards wherein each card perforation controls the action of a single warp thread for the passage of a single pick. A separate card is utilized for each pick in a given pattern. Aside from the basic complexity, jacquard weaving also has the inherent deficiency and limitation of relying upon relatively expensive equipment.
In view of the forgoing, it will be appreciated that there is a need for a side curtain configuration which can be formed on a non-jacquard loom and an efficient method for producing the same. Accordingly, the present invention represents a useful advancement over the known state of the art.
It is a basic object of the present invention to provide a substantially non-sewn inflatable curtain of non-jacquard preferably dobby woven construction suitable for use as a side curtain in a transportation vehicle.
It is a further object of the present invention to provide a bag of non-sewn dobby woven construction suitable for use as a side curtain in an automotive transportation vehicle and including woven in straight line joints to both control the expansion of the cushion and to channel the inflation media during deployment.
It is yet a further object of the present invention to provide a bag of non-sewn dobby woven construction suitable for use as a side curtain crash protection cushion in a transportation vehicle which retains gas pressure for a prolonged period of time after inflation.
In one aspect of the present invention, an inflatable airbag cushion is provided. The cushion is in the form of a bag of non-sewn dobby woven construction. The bag includes a face portion and a rear portion which face and rear portions are formed from first and second fabric layers. The fabric layers are woven simultaneously on the same loom according to weave patterns controlled by manipulation of the of warp harnesses. Each of the fabric layers is defined by a multiplicity of warp yarns running in the warp direction interposed by a multiplicity of weft yarns running in the weft direction which is substantially transverse to the warp direction. So as to maintain the bag in a relatively flat condition once inflated, and to channel the inflation gasses throughout the structure, the bag includes a multiplicity of woven in joints. These woven in joints are arranged so as to define connective points and flow barriers between the face portion and the rear portion of the bag such that upon introduction of the flow of a gas into the bag, expansion is limited by the woven in joints thereby channeling the gas to locations where inflation is desired while simultaneously restricting inflation of the bag at the locations where such woven in joints are present. At least a portion of the woven in joints preferably extend in substantially straight lines in both the warp direction and the fill direction. The woven in joints form an inflatable portion having more than four interior sides.
According to another aspect of the present invention a method for forming the bag for a side curtain protective cushion by weaving on a dobby control loom is provided whereby straight line weave patterns are repeated across the width of the loom so as to simultaneously form two layers of fabric with woven in joints disposed at selected locations across the length and width of the fabric thereby defining interconnections between the fabric layers.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are in no way to be construed as constituting restrictions on the scope of the invention as claimed.